Adhesive solid-state fermentation producing Aspergillus niger conidia on stainless-steel dixon ring supports

Area of Science:

• Biotechnology
• Industrial Microbiology
• Fermentation Technology

Background:

• Solid-state fermentation (SSF) is crucial for microbial product generation.
• Optimizing SSF conditions, particularly for conidia production, remains a key challenge.
• Existing methods often face limitations in space utilization and temperature control.

Purpose of the Study:

• To develop and optimize an adhesive solid-state fermentation (adSSF) mode for enhanced Aspergillus niger conidia production.
• To investigate the impact of adhesive components and fermentation bed characteristics on conidia yield.
• To compare the performance of adSSF with traditional adsorbed carrier solid-state fermentation (ACSSF).

Main Methods:

• Development of an adSSF mode using stainless-steel Dixon rings coated with a water-retaining adhesive and nutritional media.
• Screening and optimization of adhesive components (wheat bran powder, cassava starch, xanthan gum) using single-factor and response surface methodology.
• Comparative analysis of adSSF and ACSSF in tray reactors with online temperature monitoring.

Main Results:

• Optimal adhesive dosages determined for wheat bran powder, cassava starch, and xanthan gum.
• Experimentally achieved conidia yield was 4.2-fold higher than without adhesive.
• adSSF demonstrated a 61.5% higher conidia yield compared to ACSSF in initial stages due to improved temperature control and space utilization.

Conclusions:

• The adSSF mode significantly enhances Aspergillus niger conidia yield through improved bed voidage, temperature regulation, and space utilization.
• The developed adhesive formulation and support system offer a promising approach for industrial-scale microbial fermentation.
• Further studies may explore extended fermentation times and different microbial strains.